This document discusses neonicotinoids, a class of neuro-active insecticides. It provides details on their development, mode of action, major compounds, uses in agriculture, and effects on pollinators. While neonicotinoids brought economic benefits, concerns emerged regarding their persistence in soils and potential role in pollinator declines. The EU has imposed restrictions on some neonicotinoids for agricultural use due to risks to pollinators.

2. Presented By:
Muhahammad
Sohail
Maqsood
Roll No. 07
M.Sc. (Hons.)
Entomology

3.  Class of neuro-active insecticides
 Similar to nicotine
 Newest major class of insecticides
 Only new class that has been developed in the past 3
decades
 Developed in part because of their reduced toxicity in
comparison to organophosphates and carbamates
 Developed from unstable nitromethelane compounds
 The neonicotinoid Imidacloprid is currently the most
widely used insecticide in the world
 Used extensively in agriculture

4.  Neonicotinoids are among the most effective
insecticides for the control of sucking insect pests
such as aphids, whiteflies, leaf- and planthoppers,
thrips, some micro lepidoptera and a number of
coleopteran pests.
 Their broad spectrum of efficacy, together with
systemic and translaminar action, and a unique
mode of action, make the neonicotinoids the most
rapidly expanding insecticidal class since the
launch of the first compound, imidacloprid, by
Bayer CropScience in 1991.

5. In the 10 years that followed, six additional
neonicotinoid insecticides were launched:
 Acetamiprid (Nippon Soda, 1995),
 Nitenpyram (Sumitomo Chemical Takeda Agro
Company, 1995).
 Thiamethoxam (Syngenta, 1998).
 Thiacloprid (Bayer CropScience, 2000).
 Clothianidin (Sumitomo Chemical Takeda Agro
Company, Bayer CropScience, 2001).
 Dinotefuran (Mitsui Chemicals, 2002).

6. Acetylcholine Neurotransmitter
 Neurotransmitters are Chemical Messengers that
communicate information throughout the body
by neural system.
 They are found at the terminal region of axon in
the synaptic vesicles.
 Acetylcholine neurotransmitters are involved in
 Contraction of skeletal muscles.
 Activate glandular functions in the endocrine
system.
 Sensation of pain.

7. Nicotinic Acetylcholine Receptors (nAChRs)
 Receptor proteins respond to the
neurotransmitter, acetylcholine.
 Nicotinic Acetylcholine Receptors also
respond to drugs, including the Nicotinic
Receptor Agonist.
 They are found in the CNS and PNS, muscle
and many other tissues of many organisms.
 In insects, limited to the central nervous
system.
 Transmit outgoing signals from the
presynaptic to the postsynaptic cells.

8. Nicotinic Acetylcholine Receptors Competitive
Modulators/Agonist
 Neuro-active, systemic insecticides.
 Mimics the action of acetylcholine at nAChRs.
 Chemically bind to acetylcholine receptors site.
*Block acetylcholine access to receptor sites.
 Continuous sending unwarranted neural
transmissions.
 Receptors and cells involved in neural
transmission become exhausted and fail to
function.
 Results in paralysis and death of insects

9. The outstanding development of neonicotinoid
insecticides for modern crop protection,
consumer/professional products, and animal
health markets between 1990 and today
reflects the enormous importance of this
chemical class.
Market Environment :
The unique success of neonicotinoid
insecticides is reflected in their turnover
figures in 1990 as compared with 2010.

10. Structural Diversity :
 Seven neonicotinoid insecticides are
currently on the market:
 Three cyclic compounds,
* Imidacloprid * Thiamethoxam
* Thiacloprid
 Four noncyclic compounds,
* Nitenpyram * Acetamiprid *
Clothianidin *Dinotefuran.

11. Spectrum of Efficacy :
 The biological activity and agricultural uses of
neonicotinoid insecticides are enormous, and
numerous overviews, articles, and book
chapters have been published over the past
decade.
 Due to their unique physicochemical
properties , neonicotinoids can be used in a
variety of crops.

12. Neonicotinoids for Plant Virus Vector
Control:
 Due to its plant systemic properties,
neonicotinoid insecticides such as
imidacloprid, thiamethoxam, and clothianidin
also control important vectors of plant virus
diseases, thereby suppressing the secondary
spread of viruses in various crops.

13. Versatile Application Methods for
Neonicotinoids:
 The neonicotinoid insecticides have a high degree
of versatility, not seen to the same extent in other
chemical classes.
 Most neonicotinoids can be used as foliar sprays,
seed treatments and via soil application.
 Today approximately 60% of all neonicotinoid
applications are soil/seed treatments, and most
spray applications are especially targeted against
pests attacking crops such as cereals, corn, rice,
vegetables, sugar beet, potatoes, cotton, and others.

14. Seed Treatment with Neonicotinoids :
 Due to the development of seed treatment
application with neonicotinoid insecticides,
new opportunities have been opened up in
modern crop protection.
 Besides seed dressing, also film coating,
pelleting, and multilayer coating allow an
environmentally safe and perfect protection of
young plants against insect attack.
 With this method, application of the active
ingredient is virtually independent of the
weather and can be applied directly at the site
of action.

15. Profiles of Neonicotinoid Insecticides :
 Key crops for neonicotinoid insecticides are
vegetables, pome and stone fruits, citrus, rice,
cotton, corn, potato, sugar beet, oilseed rape, and
soybean, among many others.
 In addition to the common neonicotinoid
spectrum, each product has its specific target pest
spectrum, under additional pest spectrum.
 The commercial products also differ considerably
with respect to soil and seed treatment uses, as soil
stability is limited for some of them such as
nitenpyram, acetamiprid, and dinotefuran,
respectively.

17. Are there economic benefits from the use
of neonicotinoids?
Many studies have provided evidence that
the use of neonicotinoids can provide
effective control of a broad range of insect
pests and bring economic benefits to
farmers.
An 11 year study investigated economic
return from the oilseed rape seed coatings
with imidacloprid.

18. A large-scale pesticide usage and yield
observations from oilseed rape with those
detailing honey bee colony losses over an
11 year period, and reveal a correlation
between honey bee colony losses and
nationalscale imidacloprid (a neonicotinoid)
usage patterns across England and Wales.

19. Neonicotinoids and insect resistance :
Insect resistance after prolonged exposure is
a potential consequence of consistent
exposure to any pesticide.
Stronger resistance has been confirmed in
some populations of the whitefly, Bemisia
tabaci, and the Colorado potato beetle,
Leptinotarsa decemlineata.

20. Persistence of neonicotinoids in soils :
Another concern with neonitotinoids
insecticides (when used for seed dressing to
provide accurate targeting of the crop) was
the amount of applied chemical lost in soil
as dust during sowing.
Corn crop production was increased
worldwide for renewable energy biodiesel.

21. Unfortunately, the increased use of
neonicotinoid insecticides have been
blamed for the honeybee decline in the last
years.
Studies showed that of the 80–98% of the
active ingredient in seed dressings, which is
not absorbed by the crop, a small proportion
(<2%) is lost as dust during sowing.

22. Pollution by neonicotinoids of other
environments :
Leaching of neonicotinoids from soil after
application is lower and sorption is higher
in soils with high organic matter content.
Analytical measurements of neonicotinoids
residues detected the insecticides in
groundwater, streams, storm‐water ponds
and tidal creeks.

23. However, neonicotinoid insecticides are
absent from many groundwater and run‐off
samples collected in areas where they are
deployed.
This may be because they are only present
for a short period after application and so
are likely to be missed by most sampling.

24. Adverse effects of neonicotinoid
insecticides on pollinators :
After 2000 many research groups
investigated the adverse effects of
neonicotinoids on pollinators, especially
honey bees (nectar-foraging bees).
The first problem was about the
magnitudes of both lethal and sublethal
effects on honey bees caused by trace
neonicotinoids.

25. scientists argued that single doses under
laboratory conditions may be unrealistic,
because mass flowering crops, such as
oilseed rape, bloom over several weeks and
foraging bees are likely to ingest nectar
repeatedly.
Honey bees have suffered increased
mortality after multiple ingestions of trace
dietary neonicotinoid at field-realistic
levels.

26. The latest studies on the impact of
neonicotinoids on pollinators :
 Historically, managed honey bee
populations in the USA and Europe have
been monitored due to their vital role in
providing pollination services in
agricultural systems.
Several studies indicate that American and
European beekeepers were suffering large
annual losses.

27. Honey bees, other managed pollinator
species such as bumble bees and orchard
bees, and wild bees suffer from exposure to
parasites and pesticides, and loss of floral
abundance and diversity due to increased
land-use.

28. Decisions of EU on neonicotinoids :
 The EU has one of the strictest regulatory systems
in the world concerning the approval of pesticides
for agricultural crops.
 On the 27 of April 2018, the Standing Committee
on Plants, Animals, Food and Feed of the
European Union, after struggling for 7 months to
achieve a majority vote, expanded a controversial
ban on 3 neonocotinoids (clothianidin,
imidacloprid and thiamethoxam) on the ground
that they pose a threat to pollinators.